4.7 Dynamic Illustration of a Point Conic and a Line Conic
[Asked whether he would like to see an experimental demonstration of conical refraction.] No. I have been teaching it all my life, and I do not want to have my ideas upset.
Exit book to another website.Isaac Todhunter (1820–1910)

Point Conic

To trace the point conic, move the drag point for line d around P.
To change the point conic, rearrange the centers P and P' and the points determining lines a, b, and c.
Click on the upper right-hand corner to clear the trace or click on the reset icon.

Observe the points P and P'. How are the centers of the pencils, P and P', related to the point conic?

The above Point Conic with the conic illustrated.

To change the point conic,move P, P', and the three points of intersection from a, b, c with a', b' and c'..

Line Conic

To view the line conic, move the drag point on axes p.
To change the line conic, change the position of points A, B, and C and the axes p and p'.
To clear the trace, click on the upper right-hand corner or click on the reset icon.

Observe the lines p and p'. How are the axes of the pencils, p and p', related to the line conic?

Timothy Peil, 7 February 2013, Created with GeoGebra

4.7 Conics in the Projective PlaneBack to Conics in the Projective Plane
Ch. 4 Projective TOC  Table of Contents
  Timothy Peil  Mathematics Dept.  MSU Moorhead
© Copyright 2013 - Timothy Peil